The present invention relates to an ultrasonic treating tool for, while grasping a living tissue portion in a body cavity of a human subject, surgically treating the living tissue portion with an ultrasonic vibration and, in particular, to an ultrasonic coagulation/cutting apparatus for performing coagulation/cutting.
For example, U.S. Pat. No. 5,322,055 discloses a surgical instrument for cutting (including a resection) and coagulating a living tissue by the use of an ultrasonic vibration. The ultrasonic surgical instrument comprises an ultrasonic probe connected to an ultrasonic vibration element, a sheath through which the probe is inserted, a blade projected from the distal end of the sheath and formed by a forward end section of the probe, and a jaw pivoted at the distal end section of the sheath and a jaw confronting the blade. By the operation of the handle provided at a proximal end side of the sheath, the jaw is swung through a rod and, while grasping a living tissue between the jaw and the blade, an ultrasonic vibration is transmitted through the ultrasonic probe to the blade and the grasped living tissue is cut or coagulated.
The operation section has a fixed handle downwardly projected at a substantially right angle to a longitudinal axis direction of the insertion section and a movable handle similarly projected downwardly. By holding the operation section while the fingers of one hand grip both the handles, the movable handle is swung. These handles are downwardly projected at a substantially right angle to the longitudinal axis direction of the insertion section and are so located as to be displaced from a center axis of the sheath section, so that the hand gripping is not stable. As a result, the swing operation of the movable handle become unstable as a whole and the living tissue grasped by the blade and jaw is liable to wobble at the distal end section of the insertion section. This tendency is aggravated under the following situation.
This type of ultrasonic coagulation/cutting apparatus is directed to principally treating a film-like living tissue, solid organ, or etc., by coagulating/cutting and it is often used to grasp a relatively great living tissue portion. When the relatively great living tissue portion is grasped, a greater swing stroke of the movable handle is involved. As a result, the movable handle is liable to wobble as a whole when the movable handle is swung and, in the distal end of the insertion section in particular, the tissue-grasped area by the blade and. jaw is liable to wobble.
Further, since the fixed handle and movable operation handle are so arranged as to be projected at a substantially right angle from the longitudinal center axis of the insertion section, the hand gripping becomes unstable and need to continue firm gripping. When, in particular, operation is done over a prolonged period of time, no fatigue and numbness of the gripped hand are produced.